Identification of<i>Listeria monocytogenes</i>Genes Involved in Salt and Alkaline-pH Tolerance

Gardan, Rozenn; Cossart, Pascale; Labadie, Jean-Claude

doi:10.1128/aem.69.6.3137-3143.2003

Cited by 39 publications

(21 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An increased sensitivity of one of the mutants to alkali was attributed to disruption of the lmo668 gene; the sequence showed similarity to the yadH gene present in some gram-negative bacteria. The function of these genes is not well characterized, but it is thought that they code for membrane permeases that aid in maintaining the pH homeostasis of the cells by active transport of sodium or hydrogen ions across the membrane (9).…”

Section: Resultsmentioning

confidence: 99%

Sensitivity of Escherichia coli O157:H7 to Commercially Available Alkaline Cleaners and Subsequent Resistance to Heat and Sanitizers

Sharma

Beuchat

2004

Appl Environ Microbiol

View full text Add to dashboard Cite

The effects of seven commercially available alkaline cleaners used in the food processing industry, 0.025 M NaOH, and 0.025 M KOH on viability of wild-type (EDL 933) and rpoS-deficient (FRIK 816-3) strains of Escherichia coli O157:H7 in logarithmic and stationary phases of growth were determined. Cells were treated at 4 or 23°C for 2, 10, or 30 min. Cleaners 2, 4, 6, and 7, which contained hypochlorite and <11% NaOH and/or KOH (pH 11.2 to 11.7), killed significantly higher numbers of cells than treatment with cleaner 3, containing sodium metasilicate (pH 11.4) and <10% KOH, and cleaner 5, containing ethylene glycol monobutyl ether (pH 10.4). There were no differences in the sensitivities of logarithmic and stationary-phase cells to the alkaline cleaners. Treatment with KOH or NaOH (pH 12.2) was not as effective as four out of seven commercial cleaners in killing E. coli O157:H7, indicating that chlorine and other cleaner components have bactericidal activity at high pH. Stationary-phase cells of strain EDL 933 that had been exposed to cleaner 7 at 4 or 23°C and strain FRIK 816-3 exposed to cleaner 7 at 23°C had significantly higher D 55°C (decimal reduction time, minutes at 55°C) values than control cells or cells exposed to cleaner 5, indicating that exposure to cleaner 7 confers cross-protection to heat. Cells of EDL 933 treated with cleaner 7 at 12°C showed significantly higher D 55°C values than cells of FRIK 816-3, indicating that rpoS may play a role in cross-protection. Stationary-phase cells treated with cleaner 5 or cleaner 7 at 4 or 12°C were not cross-protected against subsequent exposure to sanitizers containing quaternary ammonium compounds or sodium hypochlorite, or to cetylpyridinium chloride and benzalkonium chloride.

show abstract

Section: Resultsmentioning

confidence: 99%

Sensitivity of Escherichia coli O157:H7 to Commercially Available Alkaline Cleaners and Subsequent Resistance to Heat and Sanitizers

Sharma

Beuchat

2004

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Gene LEPBIa2665 has close orthologues in the ART ABC2 family, which is involved in cell regulatory processes and antibiotic resistance (34). The YbiT orthologue (YkpA) contributes to resistance to alkaline and osmotic stress in Listeria monocytogenes (49). In E. coli, its orthologue (Uup) assists DNA polymerase to correctly replicate areas between direct repeats, and its deletion reduces bacterial fitness (50,51).…”

Section: Discussionmentioning

confidence: 99%

Screening of a Leptospira biflexa Mutant Library To Identify Genes Involved in Ethidium Bromide Tolerance

Pětrošová

Picardeau

2014

Appl Environ Microbiol

View full text Add to dashboard Cite

bLeptospira spp. are spirochete bacteria comprising both pathogenic and free-living species. The saprophyte L. biflexa is a model bacterium for studying leptospiral biology due to relative ease of culturing and genetic manipulation. In this study, we constructed a library of 4,996 random transposon mutants in L. biflexa. We screened the library for increased susceptibility to the DNA intercalating agent, ethidium bromide (EtBr), in order to identify genetic determinants that reduce L. biflexa susceptibility to antimicrobial agents. By phenotypic screening, using subinhibitory EtBr concentrations, we identified 29 genes that, when disrupted via transposon insertion, led to increased sensitivity of the bacteria to EtBr. At the functional level, these genes could be categorized by function as follows: regulation and signaling (n ‫؍‬ 11), transport (n ‫؍‬ 6), membrane structure (n ‫؍‬ 5), stress response (n ‫؍‬ 2), DNA damage repair (n ‫؍‬ 1), and other processes (n ‫؍‬ 3), while 1 gene had no predicted function. Genes involved in transport (including efflux pumps) and regulation (two-component systems, anti-sigma factor antagonists, etc.) were overrepresented, demonstrating that these genes are major contributors to EtBr tolerance. This finding suggests that transport genes which would prevent EtBr to enter the cell cytoplasm are critical for EtBr resistance. We identified genes required for the growth of L. biflexa in the presence of sublethal EtBr concentration and characterized their potential as antibiotic resistance determinants. This study will help to delineate mechanisms of adaptation to toxic compounds, as well as potential mechanisms of antibiotic resistance development in pathogenic L. interrogans.

show abstract

“…Es un microorganismo Gram-positivo, móvil, no esporulado y aneróbico facultativo, puede sobrevivir con baja actividad de agua (aw), a altas concentraciones de sal y multiplicarse en temperaturas de -1 a 45 °C y a pH entre 4,3 y 9,6 ± 0.2 (Todd & Notermans 2011). Adicionalmente tiene la habilidad de producir biofilms para adherirse a diferentes superficies, como el vidrio, el caucho y el acero inoxidable (Kalmokoff et al 2001, Hassan et al 2004, de tal manera que logra pasar todas la barreras diseñadas contra los patógenos en alimentos (Lou et al 1999, Gardan et al 2003. Por otra parte este microorganismo también presenta resistencia intrínseca a varios antimicrobianos; lo que hace más complejo el tratamiento de los pacientes con listeriosis (Ruiz-Bolivar et al 2008, Ruiz-Bolivar et al 2011b).…”

Section: Introductionunclassified

Electroforesis en Gel de Campo Pulsado (PFGE) para la diferenciación molecular de Listeria monocytogenes

et al. 2013

View full text Add to dashboard Cite

Identification ofListeria monocytogenesGenes Involved in Salt and Alkaline-pH Tolerance

Cited by 39 publications

References 43 publications

Sensitivity of Escherichia coli O157:H7 to Commercially Available Alkaline Cleaners and Subsequent Resistance to Heat and Sanitizers

Sensitivity of Escherichia coli O157:H7 to Commercially Available Alkaline Cleaners and Subsequent Resistance to Heat and Sanitizers

Screening of a Leptospira biflexa Mutant Library To Identify Genes Involved in Ethidium Bromide Tolerance

Electroforesis en Gel de Campo Pulsado (PFGE) para la diferenciación molecular de Listeria monocytogenes

Contact Info

Product

Resources

About